Mixed tuned hybrid bucket and related method
First Claim
1. A steam turbine rotor wheel comprising a plurality of buckets secured about a circumferential periphery of the wheel, each bucket comprising a shank portion and an airfoil portion, said plurality of buckets including two groups of buckets having respective different predetermined resonant frequencies, wherein the buckets of one group have airfoil portions with at least one recessed pocket and the airfoil portions of the buckets of the other group have at least one differently configured pocket, and further wherein said pockets are filled with polymer filler material.
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Accused Products
Abstract
A steam turbine rotor wheel includes a plurality of buckets secured about a circumferential periphery of the wheel, each bucket comprising a shank portion and an airfoil portion, the plurality of buckets including two groups of buckets having respective different predetermined resonant frequencies. A method of reducing vibration in a row of buckets on a steam turbine rotor wheel includes a) providing a first group of buckets with a first predetermined natural frequency range; b) providing a second group of buckets with a second predetermined natural frequency range different than the first predetermined natural frequency range; and c) assembling buckets of the first and second groups of buckets in alternating fashion on the rotor wheel.
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Citations
18 Claims
- 1. A steam turbine rotor wheel comprising a plurality of buckets secured about a circumferential periphery of the wheel, each bucket comprising a shank portion and an airfoil portion, said plurality of buckets including two groups of buckets having respective different predetermined resonant frequencies, wherein the buckets of one group have airfoil portions with at least one recessed pocket and the airfoil portions of the buckets of the other group have at least one differently configured pocket, and further wherein said pockets are filled with polymer filler material.
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13. A steam turbine rotor wheel comprising a row of buckets secured about a circumferential periphery of the wheel, said row of buckets including two groups of buckets, arranged in an alternating pattern about the periphery of the wheel, each group having discrete means for reducing amplitude of vibration in the row of buckets.
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14. A method of reducing vibration in a row of buckets on a steam turbine rotor wheel comprising:
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a) providing a first group of buckets with a first predetermined natural frequency range;
b) providing a second group of buckets with a second predetermined natural frequency range different than said first predetermined natural frequency range; and
c) assembling buckets of the first and second groups of buckets in alternating fashion on the rotor wheel;
wherein the first and second predetermined natural frequency ranges are achieve via differently-shaped recessed pockets in respective airfoil portions of the first and second groups of buckets;
further wherein said pockets are filled with a polymer filler material. - View Dependent Claims (15, 16, 17, 18)
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Specification